Yarn controlling device for circular hosiery knitting machines



R. TENCONI 3,194,029

YARN CONTROLLING DEVICE FOR CIRCULAR HOSIERY KNITTING MACHINES July 13, 1965 3 Sheets-Sheet 1 Filed June 26, 1962 ANN 1 5 INVENTOR. glccfikfo QM/ ATM/MP7 July 13, 1965 R. TENCONI 3,194,029

YARN CONTROLLING DEVICE FOR CIRCULAR HOSIERY KNITTING MACHINES Filed June 26, 1962 3 Sheets-Sheet 2 mmvron Ecaxbo 722/6 ow AT-I'OQMFY y 3 1965 R. TENCONI 3,194,029

YARN CONTROLLING DEVICE FOR CIRCULAR HOSIERY KNITTING MACHINES Filed June 26, 1962 3 Sheets-Sheet 3 United States Patent Ofiice l 3..., 13 .965

3,194,029 YARN CGNTROLLING DEVICE FGR CHKCULAR HGSIERY KNITTING MACE Riccardo Tenconi, Varese, Itaiy, assigner to Marcella Sessa, Varese, Italy Filed June 26, 1962, Ser. No. 205,324 Claims priority, application Italy, June 27, 1961,

11,878/61, Patent 655,564 6 Claims. (Cl. 66-140) This invention relates to circular hosiery knitting machines, particularly for producing ladies stockings, and is directed to a yarn controlling device operative during pressoffor when a yarn is taken out of action to bring the yarn from the feeding station, i.e. from the position at which each yarn is formed into a stitch for knitting the fabric, onto the top surface of the dial cap where it is gripped by a suitable mechanical or pneumatic device While waiting to be inserted into action.

There have already been proposed yarn controlling devices which consist mainly in a saw-toothed wheel or ring mounted around the dial cap to turn in synchronism with the rotary motion of the needle cylinder, so that, when a yarn guide is raised to take the related yarn out of action or when the needles are so controlled that they cannot grip the yarn, the yarn can be caught by a tooth of the ring or wheel and conveyed to a point far from the point at which the stitch was formed, to be then severed by a cutting device after being clamped or held by the mechanical or pneumatic device.

It has been observed that these known devices with saw-tooth wheels have certain disadvantageous characteristics during normal operation of the knitting machine. The saw-tooth of the ring or wheel, once they have caught the yarn, retain it and do not allow it to be released from engagement therewith until the yarn is severed by the cutter. Therefore, the distance is fixed between the point at which the yarn is caught on the toothed wheel and the point of stitching thereof in the fabric that is, the location of the last needle to knit. This fixed distance is rather long and consequently, after the yarn has been cut, relatively long trailing ends of the yarn are left in the hosiery and have to be removed by a subsequent operation after the knitting of the stocking.

Another and even more serious drawback, and one which can cause defective stockings, the stoppage of the machine and some times even the breaking of machine parts, is that in certain cases the yarn to be taken out of action is not reliably passed onto the dial cap, where it should be held by the mechanical or pneumatic clamping device, but rather passes therebelow and becomes wrapped round the transfer bits on the dial. This disadvantage may occure especially during those stages of the knitting of a stocking when the yarn is not taken out of action by the raising of its guide from the operative position, but rather by the needles being controlled so that they cannot catch the yarn fed by the yarn guide which may still be in the operative position or only partly raised from said position.

The device to which this invention relates has the object of eliminating the above drawbacks of known devices and, more precisely, of guaranteeing, in the first place, that the yarn to be taken out of action is surely passed onto the dial cap, and also of allowing the yarn to be cut at a point very near to the point at which it is stitched into the fabric so that the ends of yarn protruding from the knitted fabric will be of greatly reduced length.

In accordance with an aspect of this invention, the yarn controlling device substantially consists of a ring mounted on the dial and formed with an outer surface divided into an upper part which is smooth and of frustoconical shape and a lower part, which is connected to the major base of the frusto-conical part, and is substantially cylindrical and provided with a rough surface as, for example, by knurling or nicking.

The roughness of the lower part of the outer surface of the ring mounted on the dial is such as to frictionally constrain the yarn to move with the ring when the yarn comes into contact with said part of the surface, but without hooking the yarn as is the case with known sawtoothed wheels. The yarn is thus entrained by this roughness while the smooth upper part of the ring at the same time induces the yarn to pass over the dial cap. After the yarn has been dragged round through a certain angle from the point at which it entered into contact with the nicked or knurled part of the ring, the yarn passes over the dial cap and because of the change in the distribution of the forces acting on the yarn, between the point of stitching into the fabric (which point rotates in synchronism with the dial and hence with the yarn controlling ring) and the fixed feeding station, the yarn is released from the roughened part of the surface of the ring and moves along the latter closer to the point at which the yarn is stitched into the fabric. The excess length of yarn which is thus created is recovered by the ordinary take-up with which all feeds are normally provided.

In this manner the desired result is obtained, i.e. the reliable passage of the yarn over the dial cap and the shortening of the yarn end which remains attached to the fabric after cutting. It is manifest that this result is attained by reason of the special shape of the surface of the yarn controlline ring, and that the same result can not be obtained with a saw-toothed or any other type of deep-toothed wheel, because in such case, once the yarn has been caught on a tooth, it can no longer be easily released therefrom.

The above, and other objects, features and advantages of the invention will be apparent in the following detailed description of an illustrative embodiment thereof which is to be read with reference to the accompanying drawings, wherein:

FIG. 1 is a vertical sectional view of a circular hosiery knitting machine provided with a yarn controlling device in accordance with this invention;

FIGS. 2 and 4 are fragmentary sectional views, on an enlarged scale, in radial, angularly spaced planes of the dial;

FIG. 3 is a horizontal cross-section taken along the line IIIIII of FIG. 2;

FIG. 5 is a perspective view of a sector of the yarn controlling device;

FIG. 6 shows, partly in section, the relative positions of the dial, the yarn guide and a needle and sinker;

FIGS. 7, 8 and 9 show three successive stages in the entraining of the yarn by the yarn controlling device;

FIG. 10 is a schematic plan view of the dial cap;

FIG. 11 and FIG. 13 are partial sections of the dial, taken along the lines XIXI and XIII-XIII respectively of FIG. 10; and

FIG. 12 is a fragmentary elevational view of the dial with the yarn controlling device thereon, as viewed from the periphery.

Only those parts of the circular knitting machinefor the production of ladies stockings are schematically shown which are necessary to understanding of the invention. In other respects, the machine itself is of a well a w j 3,194,029

known type and familiar to those skilled in the art, so

that it is not necessary to give a'detailed description of its to the last needle to knit which has moved to 180. The yarn remains stretched thanks to a take-up (not shown) which takes up the excess of its length.

a In this last stage, i.e. once the yarn has been taken substantially over the dial cap, for example from position 717 (FIG. onwards, the conveying ring has practically finished, its task andthe yarn is dragged up to the "location18c by the last needle which made a stitch. As a result of the special shape of ring 15 and the geometrical to knit the fabric in the conventional manner in co-operation with the sinkers 5. Yarn guides '6 are provided for feeding a plurality of-yarns so that the type ofyarn used in the several stages of knitting of the stocking can be varied. V V

Cylinder 21is integral with a toothed wheel 8 which, through intermediate gears .9, it and 11, causes the synchronized rotation of a dial 12 disposed coaxially with cylinder 2 under thestationary dial cap of the machine} Dial 12 has radial-slots receiving transfer bits 14 which,

as is known, are used for forming the welt of the stockings. Ayamcutter with aclampi21 are, placed in a suitable.

position (FIG. 10) on the dial cap 13.

The parts so far described are; common to existing cir- 'cular hosiery knitting machines and operate in the usual manner. 1 I 7 I The yarn controlling device according to the invention consists substantially of a ring 15 fastened'by means of pins 16 or the like to the top of dial 12 containing trans fer bits 14,,so as to concentrically surround the fixed dial cap 13. Ring 15 therefore rotates in synchronismlwith dial "1 2 and also' with cylinder 2. The ring 15 mounted on'dial 12 has 'an upper, smooth, frusto-conical part 15a,

and a lower, substantially cylindrical part 15!). V

The lower part 1517 of the outer surface of ring 15 has a roughened surface in the form of shallow nicks,

notches or knurling, i ndicated by the numeral 17 (FIGS.

4,5and12). I V V The operation of the yarn controlling device is as follows: When the yarn guide 6 is lowered and needles 3 are controlled to take yarn 7 so as to form the'stitch, the

yarn passes along way from the outer surface'of ring '15 and cannot come into contact therewith.

However, during pressoff, or when the needles are so controlled that they cannot take the yarn 7, which is. fed

by one of the yarn guides, or when the guide itselfiis position taken up' by the yarn, the yarn moves out of engagement with the roughened part 17 ,(see FIG. 13) and remains in contact with the smooth part 15a of ring 15 so that-it can slide forward on this smooth part in the direction of turningof the dial.' The yarn thus tends to arrange itself on the straight line joining the point at which it leaves guide 6; and the point at which the last needle to knit is located (see position 7c of FIG. 10).

r This fact is'very important and sharply distinguishes the device according'to the invention from known devices with saw-toothed wheels or rings. By reason of the described movement "of the point of contact between the yarn and ring'lS toward the, location of the last needle 'to knit, theyarn can be cut at a point very near to the last stitch or needle.effectivetoiknit, thus eliminating the more orless' long pieces of yarn which normally remain attached to thestocking and require a further finishing operation.

The device according to the invention has been described in an illustrative embodirnenti'thereof and it is intended that it may undergo numerous variations without departing frorn'the spirit of the invention. In particular,

the roughness provided on the yarn controlling ring can be of widely varying nature so long as it is not formed of too deep notches or nicks which do not allow the yarn caught therein to be released and further so long as the roughness provides sufficient frictional resistance for the raised sufficiently so that'its yarn is taken' out ofaction,

.the'knitted 'fabric rotating with cylinder 2 entrains the yarn behind it and this yarn comes out of the. fabric at the point at'which' the last stitch was made, that -i s", at the location of the last'needle to knit atthe related feeding station. v a I After a certain angular displacement of the cylinder,

the yarn stretched between the feeding station at whichit leaves guide 6 and'the last needle'to knit at that station 7 comes in contact with the outer surface ofring 15. This a movement of initial contact is schematically illustrated in FIGS. 7 and 1,1, the thread being indicated by the numeral 7a and the location of the last needle to .knit being indicated by the numeral 'rsa. FIG. 10 shows the same situation ina plan view. a As may be seen, thread 7a touches the roughened part 17 of ring 15 at point 1% and is frictionally conveyed by the ring itself. it p 7 As ring 15 continues to rotate, its smooth, upper frustoconical part lsa'induces the yarn to pass over dial cap 13; and the last needle to knit moves to position 18b (FIGS.

and the cutter 20, and owing to the changed distribution of the forces acting on the yarn/the point of contact of the yarn with the .ring' 15 hasbeen moved from 1% 'to 1%; It will'b'eseen' that-the1point 190 is relatively close move onto the top of thedial cap andia lower, substanyarn to .be entrained by it. It is important that this roughness should not'extend over the whole outer surface of the ring but be confined to the lower part thereof which can also be slightly out of true, that is, undercut, 'so as not to impede or in anyway interfere with the passage of the yarn over'the dial cap. The smooth, frustoconical part of the upper surface of the ring induces the yarn to pass upwards instead of being dragged downwards where 'itwould become wound round the transfer bits.

In this connection, it is also important that the ring he fastenedon top of the dial and not below it.

"Iclaim:

1. Ina circular hosiery knitting machine having a rotatable needle cylinder, a dial mounted above the needle cylinder and rotatable with the lattena stationary dial cap above the diahyarn guides at a feeding station and yarn clamping and cutting means on the dial cap operative to clamp and sever a yarn when; the latter is taken out of action and passed overthe dial cap from the related yarnguide; a yarn controlling member mounted on the member having an outer annular surface for contact with pa yarn taken out of action and' which includes an upper smooth, frusto-conical part inducing the contacted yarn to tially cylindrical part of superficial roughness which extends from said uPPer'part'of the surface and frictionally urges the co'ntacted yarn to move with said annular V 8 and 10) while the point of contact of yarn 7bwith the r roughness.

p trolling memberas 1n claim 1; wherein sa d lower part of the l surface has nicks therein to define said superficial roughnes s.'.-

surface. r

"2. In a'cir cular hosiery, knitting machine, a yarn controlling'member as in claim 1; wherein said lower part of the surface is knurled to'provide said superficial 3. Ina circular hosiery knitting machine, a yarn con- 4', Ina circular hosiery knitting machine, a yarn controlling member as, in claim l; wherein said lower part of the surface has shallow notches therein to define said superficial roughness.

5. In a circular hosiery knitting machine, a yarn controlling member as in claim 1; wherein said substantially cylindrical lower part extends downwardly from the large diameter end of said frusto-conical upper part of the surface.

6. In a circular hosiery knitting machine, a yarn controlling member as in claim 1; wherein said member is in the form of a ring disposed on top of the dial and extending around the dial cap.

References Cited by the Examiner UNITED STATES PATENTS Gagne 66-145 Gagne 66149 Stack et al 66145 X Hollingsworth 19114 Mahler et al 66-140 Haberhauer 66140 X RUSSELL C. MADER, Primary Examiner. 

1. IN A CIRCULAR HOSIERY KNITTING MACHINE HAVING A ROTATABLE NEEDLE CYLINDER, A DIAL MOUNTED ABOVE THE NEEDLE CYLINDER AND ROTATABLE WITH THE LATTER, A STATIONARY DIAL CAP ABOVE THE DIAL, YARN GUIDES AT A FEEDING STATION AND YARN CLAMPING AND CUTTING MEANS ON THE DIAL CAP OPERATIVE TO CLAMP AND SEVER A YARN WHEN THE LATTER IS TAKEN OUT OF ACTION AND PASSED OVER THE DIAL CAP FROM THE RELATED YARN GUIDE; A YARN CONTROLLING MEMBER MOUNTED ON THE DIAL FOR ROTATION WITH THE LATTER, SAID YARN CONTROLLING MEMBER HAVING AN OUTER ANNULAR SURFACE FOR CONTACT WITH A YARN TAKEN OUT OF ACTION AND WHICH INCLUDES AN UPPER SMOOTH, FRUSTO-CONICAL PART INDUCING THE CONTACTED YARN TO MOVE ONTO THE TOP OF THE DIAL CAP AND A LOWER, SUBSTANTIALLY CYLINDRICAL PART OF SUPERFICIAL ROUGHNESS WHICH EXTENDS FROM SAID UPPER PART OF THE SURFACE AND FRICTIONALLY URGES THE CONTACTED YARN TO MOVE WITH SAID ANNULAR SURFACE. 